The Peace of Prague, a treaty signed on June 15, 1635, between the Holy Roman Emperor, Ferdinand II, and most of the Protestant states of the Empire, effectively brings to an end the civil war aspect of the Thirty Years' War (1618-1648); however, the war will still carry on due to the continued intervention on German soil of Spain, Sweden, and, from mid-1635, France.

The main terms of the treaty are:

* The Edict of Restitution of 1629 is effectively revoked, with the terms of the Peace of Augsburg of 1555 being reestablished as at November 12, 1627.

* Formal alliances between states of the Empire are prohibited.

* The armies of the various states are to be unified with those of the Emperor as an army for the Empire as a whole.

* Amnesty was granted to the enemies of the Emperor (with the exception of the former Elector Palatine, Frederick V).

As well as bringing to an end the fighting between the various states, the treaty also brings to an end religion as a source of national conflict; the principle of cuius regio, eius religio (“his religion; their religion”) is established for good within the Empire.

In return for making concessions in this area, Ferdinand gains the alliance of the Lutheran princes both in the struggle against the Swedish intervention, and against the expected intervention of France.

Ferdinand is also forced to make individual concessions to some of the major states to get them to sign the treaty: Saxony is granted the Margraviates of Lower and Upper Lusatia by Ferdinand in his capacity as King of Bohemia, Brandenburg has its claim to Pomerania confirmed, and even Bavaria, which has supported the Emperor throughout the war, extracts some minor concessions.

This treaty fails to satisfy France, however, because of the renewed strength it grants the Habsburgs.

France now enters the conflict, beginning the final period of the Thirty Years' War.